1. Field of the Invention
The present invention relates to a projector, and more particularly, to a projector and an apparatus and method for driving an optical scanner of the projector, which can improve system stabilization and synchronization of video data and audio data.
2. Discussion of the Related Art
Rapid progress in multimedia requires a large display screen and high definition. Recently, representation of natural colors is considered important in addition to high resolution.
It is necessary to use a light source having high color purity, such as a laser, to achieve perfect natural colors. One of devices generating images using a laser is a projector using an optical scanner. The projector scans a screen with a beam generated from a laser source using the optical scanner to form an image on the screen.
To generate a high-definition image, the optical scanner needs to operate at a high driving speed. A driving angle of the optical scanner increases when a driving signal has a specific frequency. A specific frequency of the driving signal, which increases the driving angle of the optical scanner, is called a resonance frequency. Accordingly, the driving angle reaches a maximum level and the optical scanner can be driven at a high speed when the driving signal corresponds to the resonance frequency.
However, since the resonance frequency varies due to process variation in the manufacture of the optical scanner, it is very difficult to generate a driving signal corresponding to the resonance frequency. The resonance frequency of the optical scanner may vary depending on the intensity of light input to the optical scanner in addition to process variation. That is, since the intensity of light input to the optical scanner is not uniform, the temperature of the optical scanner varies with time, and thus the resonance frequency of the optical scanner also varies with time.
Due to this varying resonance frequency, the optical scanner does not operate in response to vertical and horizontal driving signals input thereto, generating a driving error. The driving error of the optical scanner causes parts of left and right sides or parts of the top and bottom of a displayed image to be switched each other and decreases the size of the displayed image.